DESCRIPTION: (Applicant's Description) The CORE B Protein Expression Facility will provide investigators a common source of highly purified proteins and the technical knowledge for use of these proteins to meet the experimental objectives of this Program Project. The CORE will consolidate the efforts of six laboratories into one facility, eliminating unnecessary duplication of technical expertise and decreasing expresses for technical staff, while providing quality control for critical reagents. The CORE will provide active recombinant caspase, caspase inhibitory proteins (crmA, p35, IAPs), functional fragments of TNF family receptors, and functional fragments of TRAF-family proteins using bacterial and baculovirus expression systems. A formalized procedure for establishing priority reagent requests among the investigators are described. The CORE B will be located both at the Burnham Institute with bacterial expression under the direction of Dr. Welsh and at the La Jolla Institute for Allergy & Immunology with baculoviral expression under the direction of Dr. Ware.